I assume Jeff Lowenfels is smiling again. Only last week—on the cusp of a record-setting heat wave—the local gardening guru and columnist was bemoaning Anchorage’s “cold” summer of 2021. With a record-tying temperature of 76 degrees on July 16 and new all-time highs July 17-18 (including a high of 80 degrees on Sunday), our city was uncomfortably warm the past weekend, at least for those of us who prefer temperatures in the 50s and 60s.
Perhaps it has been a cooler-than-normal summer from a gardening perspective, but to one who spends his days roaming local trails and the Chugach Front Range, it hasn’t seemed exceptionally cool except, perhaps, when compared to some of Anchorage’s recent, unusually warm (and dry) summers, most notably 2019.
It wasn’t so long ago that this would have been considered a pretty darn normal summer. But it does seem we’ve entered a “new normal,” so from that perspective I suppose this may be an unusually cool season.
What interested me most about Lowenfels’ column, and why I’m writing about it here, is that he’s observed a notable drop in Anchorage’s insect population this summer. Again, he brings a gardener’s perspective.
Because I don’t garden, I can’t challenge his assertions. But I’ll note that I’ve seen both dragonflies and damselflies in municipal parks and plenty of bumblebees and butterflies up in the hills. The latter were especially visible early in the summer and I can recall telling my girlfriend Jan on at least one walk that I’d never seen so many butterflies.
Mosquitoes were pesky for a while in June and seem to have largely disappeared in July but that’s not so unusual and there are still places in the Anchorage Bowl where they can still be an annoyance.
All of this, like Lowenfels’ observations, is anecdotal. But noteworthy.
As many of you are likely aware, we’re living in a time of great loss, documented in considerable detail by those who study the Earth and its many wild inhabitants. A scientific article published in early 2021 noted, “Nature is under siege. . . most biologists agree that the world has entered its sixth mass extinction event, the first since the end of the Cretaceous Period 66 million years ago, when more than 80 percent of all species, including the nonavian dinosaurs, perished.
“A 2020 United Nations report estimated that more than a million species are in danger of extinction over the next few decades.”
If those numbers don’t shock you, check your pulse.
All of the statements I’ve quoted so far comprise something of a prelude to the article’s primary subject: evidence of substantial insect declines across much of the world, what some (mostly non-scientists) have come to call the “insect apocalypse,” a term designed to grab people’s attention.
Published in the Proceedings of the National Academy of Sciences (PNAS), the article is headlined “Insect Decline in the Anthropocene: Death by a Thousand Cuts.” Among other things, its authors examine the evidence of that decline, its many likely causes (thus the “death by a thousand cuts”), the many ways that insects benefit our species (and others), and actions being taken to better protect insects and slow if not stop the declines.
The article can be easily be found by doing an online search and I highly recommend it for those who’d like to learn more; I’ll also mention that many forms of media aimed at more general audiences have reported the article’s findings.
I present this information as a larger context for Lowenfels’ recent musings—and my own, which I’ll present here.
Before continuing, I’ll emphasize here that I’m not saying Alaska, or the Anchorage area, is experiencing significant insect declines. As far as I know (my effort including an online search), this hasn’t yet been documented.
Still . . .
I don’t necessarily disagree with Lowenfels’ assessment that insect numbers seem to be down this summer, particularly in and around local gardens and throughout his yard, places where he spends much of his time.
But while Jeff suggests Anchorage’s cool summer is to blame for the diminished insect presence, particularly important pollinators, I’ll offer a more likely culprit: chemical efforts to protect local spruce trees from spruce bark beetles.
I don’t have statistics (and don’t know if anyone does), but I’d bet that thousands of Anchorage’s spruce trees have been sprayed with toxic chemicals in recent summers. Most if not all spraying these days is done with carbaryl, a supposedly “mild” toxin that is reportedly non-toxic or slightly toxic to birds, and slightly to moderately toxic to mammals. The companies that spray carbaryl on trees and agencies that regulate them assure us the poison presents no great danger to people, as long as proper precautions are taken.
However, carbaryl is moderately to highly toxic to fish. And, as the National Pesticide Information Center bluntly states, “Carbaryl is a man-made pesticide that is toxic to insects. It is commonly used to control aphids, fire ants, fleas, ticks, spiders and many other outdoor pests.”
Here in Alaska, we can add spruce bark beetles to the list.
Of course any other insects that happen to be in the line of fire will also be killed, including important pollinators like bees. And because carbaryl hangs around in the “environment” for several days before breaking down, it can also kill insects after the spraying.
Given Lowenfels’ opposition to toxic “solutions,” including and perhaps especially to protect spruce trees, I’m surprised he didn’t consider this possibility. But the theme of his column was Anchorage’s unusually cool summer, so that’s where his thoughts went.
I have no proof that 1) Anchorage’s insect populations are notably down this summer; or 2) carbaryl spraying is to blame, if they are. But it’s possible, even likely, that the massive and widespread chemical assault on spruce bark beetles has harmed other insect populations as well, as least temporarily.
Presumably the harm will end when the bark beetle population subsides as it’s bound to do once enough spruce trees have died. But it makes absolute sense to me that for now, insect populations could have plummeted in Anchorage’s residential areas, where many people tend their beloved gardens and where carbaryl spraying has been concentrated the past few years.
One final note: in contrast to what may be happening around Anchorage, insect populations in the Chugach Front Range seem be thriving this summer. Yes, that’s yet another anecdotal observation, but one based on many trips into the hills.
Wildflowers too seem to be bountiful (as documented in recent City Wilds columns), including those of berry plants. I hope to see the fruits of pollinators’ work—including mosquitoes—when I go hunting tundra blues later this summer and into the fall. And I’ll be grateful for the crucial contributions that insects make to life as we know it. On that point, I’m sure Jeff and I agree.
Anchorage nature writer and wildlands/wildlife advocate Bill Sherwonit is a widely published essayist and the author of more than a dozen books, including “Living with Wildness: An Alaskan Odyssey” and “Animal Stories: Encounters with Alaska’s Wildlife.” Readers wishing to send comments or questions directly to Bill may do so at firstname.lastname@example.org